1. Atrial and Ventricular Enlargement
Chapter 6

2. Web Site Instruction http://www.madsci.com/manu/ekg_hypr. htm
outline/Lesson7/index.html
outline/Lesson8/index.html

3. Cardiac Enlargement Dilation stretched e.g. congestive heart failure
Hypertrophy
increase size of heart muscle fibers
e.g. aortic stenosis

4. Cardiac Enlargement Increase amount/area of cardiac tissue
How would this affect depolarization?
How could that affect an ECG?

5. Right Atrial Abnormality
Overload of the right atria
dilation
hypertrophy
also known as P pulmonale
How would this change the P wave?

6. Right Atrial Abnormality

7. Right Atrial Abnormality
Normal P wave is less than 2.5 mm tall and 0.12 seconds wide.
With right atrial hypertrophy, P waves are typically taller than 2.5 mm but not wider than 0.12 sec.

8. Right Atrial Abnormality Criteria
Tall P waves in lead II
(or III, aVF and sometimes V1)

9. Right Atrial Abnormality
Causes:
Pulmonary disease
Congenital heart disease

10. Left Atrial Abnormality
Also known as P mitrale
Left atria normally depolarizes after the right atria.
How would this affect the P wave?
wider; left atrial enlargement should prolong the P wave > 0.12 sec.

11. Left Atrial Abnormality

12. Left Atrial Abnormality
II: wide P wave
V1: negative P wave is “1 box wide, 1 box deep”

13. Atrial Enlargement

14. Left Atrial Abnormality
Lead II (and I) show wide P waves
(second hump due to delayed depolarization of the left atrium)
(P mitrale: mitral valve disease)
V1 may show a bi-phasic P wave
1 box wide, 1 box deep
(biphasic since right atria is anterior to the left atria)

15. Left Atrial Abnormality
Causes:
Valve disease (mitral and aortic)
Hypertensive heart disease
Cardiomyopathies
Coronary artery disease

16. Ventricular Hypertrophy

17. 12 Leads
Frontal Plane
Transverse
Plane

18. Normal QRS
V6?
V6?
V1?
V1?
Fig. 4-6

19. Normal QRS

20. Right Ventricular Hypertrophy
What do you think will happen to the ECG with ventricular hypertrophy?

21. Right Ventricular Hypertrophy
Consider right ventricular hypertrophy and V1
How would V1 be different?
Normal
Hypertrophy

22. Right Ventricular Hypertrophy

23. Right Ventricular Hypertrophy Criteria
In V1, R wave is greater than the S wave - or - R in V1 greater than 7 mm
Right axis deviation
In V1, T wave inversion (reason unknown)
S waves in V5 and V6

24. Right Ventricular Hypertrophy
Causes of RVH
pulmonary disease
congenital heart disease
(Emphysema may mask signs of RVH)
Posterior wall MI may also show tall R waves in V1

25. Fig 6.8
R wave and T wave in V1?
What about the axis?

26. ECG Interpretation* *See Chapter 22 Rate RR interval Heart rate Rhythm
PP interval
P wave
width, height, shape, etc.
PR interval
QRS
width (and height)
axis
R wave progression
abnormal Q waves
QT interval
ST segment
T waves
U waves
*See Chapter 22

27. Fig 6.9
R wave in V1.
P waves in II, III, & V1
T wave inversion
PR interval

28. Left Ventricular Hypertrophy
With LVH, the electrical balance is tipped even further to the left.
Tall R waves in the left chest leads
Predominate S waves in the right chest leads

29. Left Ventricular Hypertrophy

30. Left Ventricular Hypertrophy Criteria
Sokolow-Lyon Voltage Criteria
If S wave in V1 + R wave in V5 or V6 ≥ 35 mm (≥ 50 for under 35 yrs of age)
R wave > 11 mm in aVL or I...
Also
LVH is more likely with a “strain pattern” or ST segment changes
Left axis deviation
Left atrial abnormality

31. Left Ventricular Hypertrophy
Causes:
Hypertension
Aortic stenosis
not always pathological
Risks of LVH
congestive heart failure
arrhythmias

32. Left Ventricular Hypertrophy
High voltage can be seen in normal people, especially athletes
With hypertrophy in both ventricles, the ECG will show more evidence of LVH

33. ST strain patterns

34. LVH with ST strain pattern and LAE
Fig 6.10

35. LVH (in 20 yr old) without ST strain or LAE
Fig 6.11

36. Practice

37. RVH

38. Left atrial enlargement

39. Left ventricular hypertrophy (S wave V2 plus R wave of V5 greater than 35mm) and left atrial enlargement (II and V1).

40. LVH

41. Right atrial enlargement

42. LVH

43. Right ventricular hypertrophy and right atrial enlargement.

44. RVH

45. Right axis deviation (predominant negative QRS in leads I and aVl) of QRS complex and qR pattern in V1 suggests severe right ventricular hypertrophy. Sharp P waves in inferior leads and V1 indicate right atrial overload. T wave inersion in inferior and anterior leads are secondary to right ventricular hypertrophy.

46. Tall R waves in V4 and V5 with down sloping ST segment depression and T wave inversion are suggestive of left ventricular hypertrophy (LVH) with strain pattern. LVH with strain pattern usually occurs in pressure overload of the left ventricle as in systemic hypertension or aortic stenosis. Similar pattern may also occur in long standing severe aortic regurgitation, though the usual pattern in aortic regurgitation is left ventricular volume overload.
Negative P waves in lead V1 is indicative of left atrial overload. Shallow T wave inversions are seen in inferior leads. Two supra ventricular ectopic beats are also seen in the rhythm strip. They are characterized by their premature nature, a P wave of different morphology preceding the QRS (in this case merging with the T wave of the previous beat), narrow QRS complex and an incomplete compensatory pause.

47. Right atrial overload (P pulmonale) and right ventricular hypertrophy
Right atrial overload (P pulmonale) and right ventricular hypertrophy. Right atrial overload (enlargement) is manifest as tall sharp P waves in lead II and V1. The cut off values are P wave amplitude more than 0.25 mV in lead II and 0.1 mV or more in V1. Dominant R waves in V1 and deep S waves in V6 indicate right ventricular hypertrophy (RVH). Sokolow-Lyon for RVH criteria mentions that R wave in V1 + S wave in V5/V6 should be 1.1 mV or more. There is also a clockwise rotation in the QRS pattern between V1 to V6. QRS axis is around +120 degrees (aVR biphasic and lead III showing tallest QRS complex). Right axis deviation is also due to right ventricular hypertrophy. T wave inversion in inferior leads and V1 could be due to right ventricular hypertrophy itself. RVH in this case is type A with dominant R in V1 and deep S in V6. This type is seen in pulmonary stenosis. Type B RVH shows dominant R waves in V1 without deep S in V6. Deep S in V6 without dominant R in V1 seen in chronic obstructive lung disease with cor-pulmonale is called type C RVH. (Strictly speaking the types are classified depending upon vector cardiographic features and not based on scalar ECG)